In Vitro Activities of Tedizolid and Linezolid against Gram-positive Cocci Associated with Acute Bacterial Skin and Skin Structure Infections and Pneumonia.
Antimicrob Agents Chemother. 2015 Jul 27;
Authors: Chen KH, Huang YT, Liao CH, Sheng WH, Hsueh PR
Tedizolid is a novel, second-generation oxazolidinone with potent activity against a wide range of Gram-positive pathogens. A total of 425 isolates of Gram-positive bacteria were obtained consecutively from patients with acute bacterial skin and skin structure infections (ABSSSIs) or pneumonia. These isolates included methicillin-susceptible (MSSA, n=100), -resistant Staphylococcus aureus (MRSA, n=100), Streptococcus pyogenes (n=50), Streptococcus agalactiae (n=50), Streptococcus anginosus group (n=75), Enterococcus faecalis (n=50) and vancomycin-resistant E. faecium (VRE) (n=50). Minimum inhibitory concentrations (MICs) of tedizolid and linezolid were determined by the agar dilution method. Tedizolid exhibited better in vitro activities than linezolid against MSSA (MIC90s, 0.5 vs. 2 μg/ml), MRSA (MIC90s, 0.5 vs. 2 μg/ml), S. pyogenes (MIC90s, 0.5 vs. 2 μg/ml), S. agalactiae (MIC90s, 0.5 vs. 2 μg/ml), Streptococcus anginosus group (MIC90s, 0.5 vs. 2 μg/ml), E. faecalis (MIC90s, 0.5 vs. 2 μg/ml) and VRE (MIC90s, 0.5 vs. 2 μg/ml). Tedizolid MICs against E. faecalis (n=3) and VRE (n=2) intermediate to linezolid (MICs, 4 μg/ml) were 1 μg/ml and 0.5 μg/ml, respectively. Tedizolid MIC90s against S. anginosus, S. constellatus and S. intermedius were 0.5, 1, and 0.5 μg/ml, respectively and rates of susceptibility based on the US FDA MIC interpretive breakpoints to the isolates was 16%, 28%, and 72%, respectively. Tedizolid exhibited 2-4 fold better in vitro activities than linezolid against a variety of Gram-positive cocci associated with ABSSSIs and pneumonia. The lower susceptibilities of tedizolid against isolates of S. anginosus and S. constellatus than against S. intermedius in Taiwan were noted.
PMID: 26248355 [PubMed - as supplied by publisher]